Multiple chamber fluid container



ul 23, 1946. w LI KA f 2,404,578

MULTIPLE CHAMBER FLUID CONTAINER Filed July 26, 1940 2 Sheets -Sheet 1INVENTOR Maj/v @Zafsta BY Q2 ATTORNEYS July 23, 1946. J w.| -1-sKA'2,404,578

MULTIPLE CHAMBER FLUID CONTAINER Fild July 26, 1940 1 2 Sheets-Sheet 2ATTORNEYS Patented July 23, 1946 MULTIPLE CHAMBER FLUID CONTAINER JohnW. Liska, Akron, Ohio, assignor to The Fire i stone Tire 8r RubberCompany, Akron, Ohio, a

corporation of Ohio Application July 26, 1940, Serial No. 347,713

8 Claims. (Cl. 152-342) This invention relates to fluid retainingcontainers for pneumatic tires and more particularly other and permitequalization of pressure between the chambers during operation. However,in these previous devices therelative size of this passage between thechambers has been deliberately kept small because it was thoughtnecessary in order to retain its safety characteristics. In the event ofa blowout or rupture in the outer chamber, a large passage would permitthe air to rush out so fast from the inner chamber that. the highlydesirable safety characteristics would be substantially nullified. Agreat disadvantage of such a very small passage is that considerabletime is necessary to effect inflation. Also with a very small passage itis practically impossible to get enough of the pressure fluid out of theinner chamber to permit demounting of the tire because as the pressurein the chamber continues to decrease, its rate of flow through the smallpassage progressively becomes less and less. Another dis advantage isthat unless the efiective cross sectional area of the passage is atleast as great as the eifective cross sectional'area of the primaryinflating valve for inflating the tube from the external source, apressure differential will develop between the two chambers and aninaccurate indication of the pressure in'one of the chambers willresult.

Accordingly, a major object of the invention is to overcome the abovedisadvantages. 1 More specifically, the objects are to provide a doublechamber safety tube, with means for 'nOrmally permitting rapid inflationand deflation of both chambers of the tube while controlling the flow offluid from the inner to the outer chamber in the event of a blowout orrupture in the outer chamber; to provid such a double chamber safetytube with a passage or passages between the two chambers of totaleffective cross sectional area, at least as great, but preferablyslightly I greater, than the effective area of the passage of passagesbetween the chambers; to provide an improved valve means in a safetytube of the 2 character mentioned, between the two chamber which will beresponsive to a pressure differential to control the flow of fluid fromthe inner to the outer chamber in the event of a blowout or rupture inthe outer chamber; to provide such an improved valve means which will bepositive in its action, will be inexpensive to manufacture and will beof such shape as to facilitate its incorporation in a safety tube of thecharacter above mentioned. e

Other and further objects will be readily apparent from the followingdescription, considered in connection with the accompanying drawings, in

which: 7

Figure l is a perspective view of an inner tube embodying the invention,a part thereof being broken away to show the underlying structure;

Figure2 is a section, on a larger scale, on the line 22 of Figure l.

Figure 3 is a section, on the same scale asFigure 2, on the line 3-3 ofFigure 1, to illustrate the relative size of the cross sectional areasof the primary inflation means and the passage between the two chambers.

Figure 4 is an enlarged Sectl0n 0f the valve means. between thechambers, shown in Figures 2 and 5, looking in the direction indicatedby the arrows 4-4 of Figure 6; v

Figure 5 is a plan View of the valve means shown in Figures 2 and'4,looking in the direction indicated by the arrows 5-5 in Figure 2;

Figure 6 is a modified form of the embodiment shown in Figures 4 and 5;v

Figure '7 is a vertical section, on the line 1-1 of Figure 8, of afurther modified form of the valve; and

Figure 8 is a plan view of Figure 7.

An embodiment of thelpresent invention is 11- lustrated by thefundamental elements of the combination; an annular tubular body I l ofelastic rubber composition or composition having similarcharacteristics, forming an outer chamber ill; a concentric wall l2which serves as part of a wall of'an inner chamber l5 inside of theouter chamber; a primary inflation valve l3 by which pressure fluid froman external source may be introduced into the inner chamber 15; and apassage [4 in the wall I2 with which there is associated a valve It tocontrol the flow of pressure fluid from the inner to the outer chamberin the event of a blow out or rupture in the wall of the sure fluidthrough the valve I3 in either direction, the valve I6 being responsiveto a pressure difierential to be forced toward the wall l2 when therebearing on th invention, they merely being pres.-

ent to complete the communication between the inner and outer chambers.

The present invention is adaptable to;

of a multiple chamber tube n'd'i'sjnot hto the particular type oftubeshbwn'for purposes of illustration. In the illustration shown, the

wall I2 is made of substantiallyinel'astic rubber-.-v

ized fabric similar to the conventional tiracasing V plies in which thereenforcing elements or cords" are arranged at an angle to the axis ofthe tube and is joined by vulcanization to the outer tubular body lladjacent the respective bead" regions of the tube. indicated at 18, [8.However, as far as the basic aspect of this invention is concerned,

. it is not necessary to have the margins of the wall joined to thetubular body ll'. It is only necessary that the wall l2 'be arrangedinside of the'tubular body H and serve as a partofl a common wallbetween the outer chamber and achamber disposed radially inwardly of thetread part of the outer wall ll. 'In'a safety 'tube'of this type,the'inner'wall l2 ismerely adapted to be disposed in a'position toprotect it from the impacts and possibl punctures to which the treadpart of the tire is'subjected and is adapted to retain a certain portionofthe original fluid pressure land to serve asa boot on reenforcement'for a'rupture in the tire casing-- when the latter ruptures. 7

' The valve I5, as shown, is in'theform of-a cir- "cular rubber discand-has a peripheral flange 2| which is integrally bonded by"vulcanization to g the inner. face ofthe walll2 and is preferablydisposed substantially concen-trictothe passage l4, but in any event isdisposed sothat the passage I4 is fwithin the region 'where' the flange21- is joined to the'wall [2. The valve l6'is generally located. 'I'hisconcavo-convex region is. readily flexible to enable operation of'thevalveJfi without subjecting any part thereof to tensilestrains.

Axially of the concavo-convexregion 2 2,..aplanar disc portion23.'is.integra1ly.formedandshas an annular rib 24 on one side thereof,which serves as the sealing element of the valve. Theirib. 24

is adaptedto "contact. the wall. l21t0 co'ntrolthe flow offluid pressurethrough the passage. I41,

so that it is necessary that the valve; Iii be so disposed. on the wall12 that. this rib. 24. completely'surrounds, the passage H3 in order forthe j valve to function most efficiently. The disc portion 23, while of.flexible rubber, isofsufiicient stififnessito prevent it from beingforced through 1 the. passage: l4, and. is providedwith anaxial bl'eederorifice 2.5..which provides a predetermined minimum passage between. the[two chambers when the valve 16 closes. against the wall- I2. 'It

i will be, readily apparent that sincethe valvelfi is arranged on theinner face of the wall 12, any

appreciablygreater pressure in the innenchamber l5; than in the.outerchamber l-lLwill force the central partof thevalve lfioutwarytoward i .the,wall l2juntil= the annular rib 24c0ntacts1the latter andcloses communication between the in- 4 ner chamber and the outer chamberexcept for the small orifice 25. The orifice 25 is desirable to insureequalization of pressure between the two chambers and to permit the slowescape of fluid pressure from the inner chamber in the event of arupture in the outer chamber for the purpose of discouraging the driverfrom continuing to drive on'the' inner chamber. It, will be readilyapparentth'at any mechanical equivalent of the orifice 25 can be usedwithout departing from the spirit of the invention. For example, insteadof ,thaorifice. a; recess. y be provided in the an-v nular rib 2;} or aprojection may be provided,

either-on the, ribfor on the surface of the wall 1 t o prevent the;valve it from completely closing the passage between the two chambers.

Thejpassage. M; in the wall [2 has an effective cross sectional areawhich is preferably slightly greater than the cross sectional area ofthe primary inflating valve [3. In considering the effective crosssection, the pressures to which these valves are subjectedare takenin-toconsideration. For. instance; if; the physical area ofthe valve l.3l andthe valve I6were exactly the same, the effective cross sectional area ofthevalvel-S, for. all. practical. purposes, would be greater than thatof: the. valve lfi, becausethe inflating valve is. will be subjected tothe total-p s of: t source. of inflatingfiuid; the.areasare equal andthevalve I 3;is.connectedtoahexternal source of high fluid pressure,arpressure differential will develop. between: the inner and; outerchambers. It is. definitely.. an obj ectof: this invent-ionrto avoidthis. Eorthisreason, the crosssectional area. of thepassage. l4.isenough larger than. the area of. the valve l3; to .insurethat. no.substantialpressure differential between the. two: chambers willdevelop.when.the.tube.is being; inflated; from the external source. I H

Theimproved inner tubeismounted in. apneumatic. tire. casing intheusualv manner. During inflation of thetube, airpassesfirstinto. theinner chamber l,5 and; then. through the. apertures l1 inthevalv fiand.the.passage,-v I 4 in thetwall. I2 into the; outer, chamber. LII, the.valve In. remain.- ins ones eca se .of. thesubstantiall hqual. fluidpressure .onboth sidesef tlrlerwallv I2. Theearr ran ementenables thetwo .chamber of; the tube concurrently; to be, inflated; Without any.;s.ubstan:- ti l, pre su e. difierent al. developing between; the twochambe s: The isznorvtaste Qf timeesuch as..-Qccl rs.vr en beair;.requiredito.passthroush verx-sm lt aperturesbetween; the twoechambersndinflation hr u h thesririmaryinflatingevalye ireql ir sn l n rtimethamthat required: for inflating a single chamber tube. Moreouer;there isno n fii llity; inaccurate indication. of the fluid pessllreiin.eith'enofrthe.twdchambers. The pressuredndicated at.thevalve. l 3ewilltalways be, a cqrrect-indicatiom of; the.fluidz-pressure- .in both chambers.

Wh n het ire and .tube are in inflated condition and-a blowout or;ruptprebccurs, the. outer chamber I 0 ofZ-the. tube. is. rapidly;deflated; and causes-a pressure ldifierential; between-the cham.- ersIll-and I5; nressuredifierennal:causes the,- centralportion 2 3; ofthevalve l 6.;to. be .forced toward the...w.al1. l2: so thatithe;annular..rib-2..4 will contacttheinside ofgtherwall. IZEand thereby r aly. Ethics. the rate..- of flom. ofi the: pressure fluid. from. the.inner .to .the.-. outer .chamber. As

explained above,v however,.:the .valve. is designed with a by-pass 25;to permit the, pressure from .the.-,inner.chamberto; gradually escapetherefrom;

Th'etimerrequired for; complete deflationvof the inner chamber may befrom approximately one 5 to six minutes Itshould-belongenough toenablethe driver-of the-vehicleto bring the latter under control, or toa'stop, but not long enough to encourage him todrive on the partlydeflated tube, since this would eventually result in serious damage tothe tire and tube. 1 l

i The valve between the two chambersmay take varied forms, as shown bymodifications of Fig;- ures 6,7, and8.

In Figure 6 the valve 26 "is shown-withathickenedcentral region 33-having an aperture .35 therein. The undersurface of the-central region33 is planar." Otherwise this modification is similar to 'thatof Figure4. N

Figures 7 and8 show a further modified form in 'which thevalve 36comprises an annular disc similarto that of the previous figures, buthav ing a recess 31which'spaces the'central region 43 fr'om' thedividing wall |2-betweenthe inner and 'outer chambers when the outeredg'e ofthe recess. the outer area of the' ce'ntral region will beflexiblef to facilitate operation of thevalve against thewallvl2. -Thevalveiia a thickened portion 44. which servesfas thevalveelement and itis preferably of sufficient thickness'to prevent it from being pushedinto. theaperture L4 in the wall, in the event of high pressuredifferential when the outenchamberblows out or ruptures. This thickenedportion could serveas' aweighted valve elementto close in response tocentrifugal force when the wheel operates above a predeter mined speed.The apertures 41v areto provide communication between the chambers,since the valve 38 is placed over; the aperture [4 in the wall I2.The-side of: the central region 43 ad- 'J'acent the wall 12 is providedwith a transverse rib 48 which prevents the valve 36 from tightlyclosing the aperture Mn It-is desired tokeep the valve from closingtightly in order to discourage a drivernfrom continuing to'drive thevehicle after the outer chamber .has blown out or ruptured. It is to beunderstood that-' the combined area or. the apertures 41 is greater thanthe area of the passage [4 in the wall l2. As will be readily apparentfrom the foregoing description, the valve 36 will be forced against thewall I2 to reduce the flow of air through the passage I4 in the eventthe outer chamber blows out. It is to be understood that the valvesshown in Figure 7 and 8 will be attached to the underside of the wall 12in a manner similar to the embodi ments previously described.

It is to be understood that where, in the specification and claims, thesingular is used, the plural is also contemplated where the cumulativeeffect of the plural elements is the same as that of a larger singleelement.

The description which has been given, recites more or less detail of theparticular embodiments of the invention, which are set forth as new anduseful. However, it is to be understood that the invention is notlimited to exact details of construction, because it is manifest thatchanges and modifications may be made within the scope of the appendedclaims without departing from the spirit of the invention. Also, theinvention is not limited to the applications or uses described, but itis to be understood as contemplating all inherent uses or functions.

What is claimed is:

1. An inner tube for pneumatic tires, said inner tube comprising anouter chamber and an inner chamber, a Wall dividing said chambers, valvemeans operably associated with said passage responsive to.pressuredifferential between said chambers'ifor controlling the ratebf'fluid fmw through said passage, said valve means comprisin an annular1 disc having its imiter; edge secured -to the inside iof said wall in aregionisiirrounding said passage,-' said va'lve'-liavihg--'a cen tralrecessed :portion 'h'aving a surface 'adjacent to-butrspaced from saidwallover said passage;

thesurface of said recessed portioh 'adjacent'to contactsaid .wall uponcollapse of said flexible material, a i port: in I said flexiblematerial posi; tioned toqr'egister.with said opening in s'aid sep'aratingwall upon collapse-"of said flexible material, the collapse ofsaid' flexible materialbeing caused b aquick release of substantial airpres sure onthe otherside of said wall, movement of the flexiblematerial ofthjevalve againstthe sp-f arating, wall sealing the vents,the port means maintaining ail-"communication with the opening inzsaidseparating wallat all times. j Means :for controlling -moverne'nt of anthrough; :aseparating wall having anv opening therethroughbetween airpressure chambers of ajpsafety tube or the like comprising a substantially collapsible valve chamber over said'o'pen ing on one side of saids'eparating wall, saidv'alv' chamber having a cover-"portion,vent'means-in said cover-portion forthe passage of air into {and fromsaidvalve chamber, flange means between the vent means and th openingpreventing substantial movement of air' through said vent means .tosaidopening'when' said valve chamber'is collapsed, a restricted portthrough said cover positioned to register with the opening, the covernormally remaining spaced from said separating wall, and said coverbeing adapted under difference in pressures such as is caused by suddensubstantial failure of the air pressure on'the side of said acollapsible valve chamber over said opening on one side of saidseparating wall, vent means for the passage of air to and fromsaidcollapsible valve chamber, means in said collapsible valve chamber,positioned to prevent the passage of air between said vent means andsaid opening upon collapse of said valve chamber, a restricted port insaid valve chamber normally registering with.

said opening for the passage of air regardlessof the collapse of saidvalve chamber, said valve chamber being adapted to collapse upon thesudden removal of substantial air pressure on the other side of saidseparating wall from said valve chamber.

5. Means for controlling movement of air through a wall of a safety tubeor the like comprising'a separating wallhavinga po'rttherein torgtheinterpassage 50f fluid therethroug-h; aflexe ible collapsible, coverarranged over said port and r arcane w secured torsaid wall ononeside-thereof,- said coyerg and wallibeing normally: spaced from. oneanotherland forming aivalve jchambena vent pase sa eyin said cover,connecting-maid valve chamber w th the exterior of said chamber-on-saidone side; i isaid iwall and outrofgregister with-said .pgrt, ;a bleedopening; insaid cover 1 connecting 1 walltinterr-uptethe interpassa'geot fluidvbetween thepne side of H saidlw'all exteriorly of said:chame ber andtheotheriside,except through. saidbleed 7 opening andportini registry therewith r 6, Aivalve for ;a pneumatic'tireinnertubesuch ascemprises an internal non-'elasticwall dividing it intoinner,andouter chambers: that are in communication; with each other through a;passage in; said wall, said valve consisting or a uni-- tar shallow,dish-shaped rubber structure comprlisingta peripheral ,flange adapted tobe at-e tached to said internal tubewa ll in concentric relation tofithepassage therethrough with, the

bottom portiongoi said structure-spaced apart therefrom, said rubberstructure being collapsible under impetus of pressure differential onopposite :s a 7 permit pressure fluidtapassfreely therethrough withoutcollapsing said rubberistructure in the absence of substantial pressuredifierentia-l on .012.-

posit'e side's'of said rubber structure; a 7 7. A valve in combinationwith a separating wall for an inner tubeof the twocompartment type saidtube having an inner and outerwall,

a port in the inner wall through which the tube inflation pressure insaid compartments normally equalizes, a rubber valve portion secured tothe inside surface; of the inner-wall and being disposed oversaid port,said" valve portion having a bleede'r hole aligned with saidport, saidhole ibe-i ing relatively small in relation tosaid port,t said valveportion having its :edge portions permanently attached to saidinsidesurface and having its centra1 portion normally spaced apart there-,from thereby forming acollapsible valve chamber, an annular ribencirclingqsaid' hole-anduprojecting'into ,said' chamber and beingadaptedto seatyonasaicl inner wall about said port when said chamber isincollapsed conditionwith said port, a

I plurality .of apertures; forined'throu'gh said .rub-

sides thereof, a bleederi orifice through-the ter) 7 portion ofsaidrubber structure, a continuous annular rib about said orifice. andsp'aceditherefrom formed inside and on the. bottom portion of saidrubber structure, aplurality of apertures: formed through the wall ofsaidrubber: structure-intermediate saidrib and. said flange; thetotalcross sectional area ofsaid ape-rturesbeing such as to her-valveportionain the area threof' outs ide' the circle. formed by said rib,said apertures having at least asrgre'atlcombin'ed efiective' cross sectional areaas the cross sectional area ofrs'aid port. v m p t V 8.. Avalve in- .com'binati'on with a separating wall havingfanopenintherethrough, comprising a collapsible valve wall providing a chamberover said opening on one'side ofsaid separating wall, vent means forthewpassage of air -to' and. from saidvalve chamber means carriedby saidvalve chamber wall positioriedfor reducing the effective cross-sectionalarea of said-opening in said wall upon collapsev of said valve chamberwall and providing a passageway for air regardless of the; collapse ofsaid chamber wall said valve chamber wall being" adapted to collapseupon sudden removal of substantial air pressure on the other side ofsaid. operating Wall from said Valve chamber. V V

a JOHN W. LISKA:

